allow spilling >31 regs. apprently i386 was always safe as fpu regs are fakes. needed by hppa (and i think also powerpc) or any other arch that employs callee-save regs of >31 numbers (per defines ;). most of the archs are simply using ipp_regs[0] as they do have less than 31 regs or otherwise need no spilling. ragge@ told me to commit this in september and it seems to work (: